Make SupportsUserData sequence-affine instead of thread-affine.

base/supports_user_data.cc

Index: base/supports_user_data.cc
diff --git a/base/supports_user_data.cc b/base/supports_user_data.cc
index 6ba3ff6c8db8f5bdf85a646c3880d3f09c486c7c..d5110555333a0a00ec2c2c93f696524f01ebc591 100644
--- a/base/supports_user_data.cc
+++ b/base/supports_user_data.cc
@@ -9,12 +9,13 @@
 namespace base {
 
 SupportsUserData::SupportsUserData() {
-  // Harmless to construct on a different thread to subsequent usage.
-  thread_checker_.DetachFromThread();
+  // Harmless to construct on a different execution sequence to subsequent
+  // usage.
+  sequence_checker_.DetachFromSequence();
 }
 
 SupportsUserData::Data* SupportsUserData::GetUserData(const void* key) const {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(sequence_checker_.CalledOnValidSequence());
   DataMap::const_iterator found = user_data_.find(key);
   if (found != user_data_.end())
     return found->second.get();
@@ -22,21 +23,21 @@ SupportsUserData::Data* SupportsUserData::GetUserData(const void* key) const {
 }
 
 void SupportsUserData::SetUserData(const void* key, Data* data) {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(sequence_checker_.CalledOnValidSequence());
   user_data_[key] = WrapUnique(data);
 }
 
 void SupportsUserData::RemoveUserData(const void* key) {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(sequence_checker_.CalledOnValidSequence());
   user_data_.erase(key);
 }
 
-void SupportsUserData::DetachUserDataThread() {
-  thread_checker_.DetachFromThread();
+void SupportsUserData::DetachFromSequence() {
+  sequence_checker_.DetachFromSequence();
 }
 
 SupportsUserData::~SupportsUserData() {
-  DCHECK(thread_checker_.CalledOnValidThread() || user_data_.empty());
+  DCHECK(sequence_checker_.CalledOnValidSequence() || user_data_.empty());
   DataMap local_user_data;
   user_data_.swap(local_user_data);
   // Now this->user_data_ is empty, and any destructors called transitively from